Map vector line element corner reasonability drafting method based on graphics processing unit (GPU)

Abstract

The present invention relates to a symbolic rendering technology of the GIS field and the digital map making field, and provides a map vector line element corner reasonability drafting method based on a GPU which realizes the linear vector element reasonable drawing based the method. The method comprises the following steps of firstly generating a corresponding color structural table according to a map symbol unit needing to be filled, and making a special column as a background column in the color structural table; then constructing a line triangulation network after triangularization according to line widths, transmitting a U parameter along a line direction and a V parameter vertical with the line direction to each vertex in the triangulation network, adjusting the U values when the vertexes are valuated with the U values and if the filling at the corners is the background column; and finally transmitting the color structural table and the U-V parameters to a shader program, and carrying out the per pixel drawing on the line elements based on the color structural table by utilizing the Shader language and according to the U-V value of each vertex.

Description

technical field [0001] The invention relates to a symbolic rendering technology in the fields of GIS and electronic map, and provides a method for drawing rationality of corners of map line elements based on GPU (Graphics Processing Unit) programmable pipeline and Shader language. Background technique [0002] The symbolization method of geospatial entities is an important research content in the field of geographic information and cartography. Compared with commonly used point symbols and surface symbols, line symbols are often more difficult and time-consuming because they need to be filled and drawn along the direction of linear elements. In addition to the commonly used solid lines and dashed lines, the line symbols required in map representations are more complex. For example, the linear symbol of a major urban road is a double-line graphic entity with a border; the railway symbol is a black and white graphic entity with a border; the single-sided boundary line symbol ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is based on the GPU programmable pipeline and shader technology, aiming at the problem that the vector line element is prone to unreasonable drawing at the corner, breaking through the tradition and using a variety of different interval modes to avoid redrawing and missing drawing at the corner The method realizes the pixel-by-pixel drawing of vector line elements based on the symbolic structure, and performs corner rationality processing during the drawing process

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